If so, then the fact that you can have two involute shaped mating surfaces as valves (almost no sliding, just a rolling contact), and a rotor that could be statically and dynamically balanced to almost zero vibration, would be amazing.
At this point, most of the parts of an EV are quite mature, and the overall system is a lot more straightforward than a conventional ICE car. A rear motor (or pair) can drive the real wheels without a transaxle or multi-speed transmission. Traction control can be achieved by rapidly adjusting torque. Regenerative breaking massively increases brake lifetime and reduces particulate emissions. 4WD is relatively inexpensive and increases efficiency (because the front and rear motors can be optimized for different operating regimes, and one can be turned off whole cruising). An electric A/C compressor can operate at the optimal speed for the A/C without regard for driving conditions. A small battery pack that can produce plenty of power for bursts of acceleration under anything except racing conditions is essentially a commodity.
So I think a series electric car with a 150kW (not kWh, and only supplying 150kW in brief bursts) and a small, highly efficient 30-40kW gasoline engine would be fantastic. And that engine would not need to have low efficiency and high emissions while warming up at low speed — when it turns on, it could immediately run at its optimal operating point even if the car is stuck in traffic.
Heck, a manufacturer could sell the engine as an optional feature — many customers could simply skip the engine and drive the car as a short-range EV.
The Chevrolet Volt used a similar principle as well, as opposed to the Prius and its more complicated mechanical duel-drive train.
This is different from pure electric drivetrains like diesel-electric locomotives where the fuel is only used to generate electricity and all of the propulsion is by electric motors.
A 30kW generator will produce 30kWh in an hour, which is enough energy to drive 120 miles and well above any average travel speed required.
In ideal conditions a 20kW generator would be enough to drive with a completely depleted battery at highway speeds, and a 10kW generator would be enough to significantly extend your range.
Which might be necessary.. a 30kW generator running at fult tilt while sitting at a stop light might be a rather unusual experience. Also looking at commercial extended duty 30kW generators makes me wonder where you're going to put that on an already 4,000lb car.
This setup is already used in diesel-electric locomotives and submarines but hasn't really been applied to other transport systems for various reasons. It's something I've been working on as a side project although maybe it's time to launch it as a startup.
It seems like this thing could rev really high, since there's no herky-jerky motion.